Process of making rubber sleeves



1932' M. B. SALISBURY 1,835,951

PROCESS OF MAKING RUBBER SLEEVES Filed Feb. 24. 1931 Patented 1, 19132 1,885,951

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MOSES B. SALISBURY, OFCHIGAGO, ILLINOIS v rnoonss or MAKING RUBBER SLEEVES Application filed February 24, 1931. -Seria1No. 517,746.

My invention relates to rubber sleeves, such substantially the contour of Fig. 1. The presas are used by linemen working along electric sure is then applied to the material, and this lines, to avoid receiving shocks. pressure is in the neighborhood of 200 tons These sleeves are usually slip-011 affairs over the area; however, since the mould it- 5 which may be connected together over the self is flat, no difficulties are encountered in 55 shoulders in such a fashion as to hold them applying the pressure evenly over the surin place. In order for them to conform someface and retaining the resulting product of what to the arm, they are made tapering from substantially uniform thickness. one end to the other and somewhat longer on Havingplaced the material in the mould one side where they go over the shoulder than and applied pressure, it is then vulcanized 0 on the opposite side where they fit underneath while under the same pressure. The seam the arm. portion indicated at 5 in the drawing is To be efiicient as an insulating device, they roughened by a rotary buffer and a cement in are preferably made of all rubber without liquid form consisting of rubber of the same the use of any fastening devices that might material as the sleeve and a solvent is applied provide a path through the rubber for the to both edges 5 and 6. The article is then electrical current. hung up and allowed to dry. Then the two It is also essential that they be of very light edges 5 and 6 are overlapped as shown at 7 uniform quality as the weight is of great imin Fig. 2 and slightly pressed into contact by portance to the user. a hand roller. Immediately after this is done, 7

Owing to the tapering and unusual form the sleeve is turned inside out and placed of the article, the moulding of it in the finin a hot press with a cloth separator between ished form is of doubtful utility for the purthe top portion 8 and the bottom portion 9, pose. This is owing to the fact'that to have and kept therein at low pressure for say two 2 the mold closing under the normal pressure minutes in order to cure the seam. required upon a form of such an odd shape Thus it will be seen that I have provided practically precludes uniform thickness in a method of making a sleeve which avoids the product. the necessity of providing or attempting the One of the purposes of this invention is to use of moulds for making the tubular article 30 provide a method whereby the artlcles may which moulds would have to close on the un- 55: be moulded under the requisite pressure and symmetrical form taken by the completed still combine into the final form without the article. loss of strength or insulating quality. 7 Having thus described the invention, what It is also a purposeof this invention to pro- I claim as new and desire to secure by Letters :25 vide a sleeve of this character of substantially Patent is: uniform thiclmess and strength throughout 1. A method of forming rubber sleeves for its surface. covering and insulating the arms of workers In order to aid in understanding the inwhich comprises molding the rubber under a vention, I will refer to the accompanying very high pressure into a flat blank of subdrawing wherein stantially uniform thickness and shape so that Fig. l is a plan view of the moulded blank when the side edges are joined the tubular prior to its being formed in the sleeve shape; member so formed will make a tapering Fig. 2 is a cross section of the blank in one sleeve, removing the blank from the mold,

stage of the operation; and applying rubber cement to the side edges of 45 Fig. 3 is a cross section of the blank in the the blank drying the cement, and overlapping final stage. and pressing them together turning the sleeve In carrying out the invention, I preferably thus formed inside out, and applying heat and take the raw material, namely rubber, cala low pressure thereto to complete the bond ender it to proper thickness, cut it to shape, between the edges.

50 and place it in a mould which is fiat and 2. The method of forming a tubular molded rubber member which because of its shape cannot readil be molded of uniform thickness in final cm which consists in molding at high pressure a flat blank of uniform thickness and an offset side edge cementin the side edges with rubber cement drying t e same, over-la ping the side edges to the extent of the ol at; inverting the member and curing the seam by the application of heat at a, low 10 pressure.

In witness whereof, I hereunto subscribe mg; name this 10th day of February A. D 19 1.

MOSES B. SALISBURY. 

